ADRB2 and exfoliation syndrome: Autoantibodies targeting the adrenergic β2-AR in glaucoma suspects and patients with glaucoma: pseudoexfoliation syndrome (PEXS), pseudoexfoliation glaucoma (PEXG), ocular hypertension (OHT), primary open-angle glaucoma (POAG), secondary open-angle glaucoma (SOAG), and pigment dispersion (PD).